Benson hired 3 of Bussard's employees before he left SpaceDev, and they are still there. He is still working with Bussard to help him raise money, but only as an aside.

He needed to raise more money and wanted to avoid diluting the stock of SpaceDev, so he started a new company called Benson Space Company which contracts vehicle construction back to SpaceDev. The following month he did leave SpaceDev but he didn't say anything about selling his shares. He talks about it early in the program, which you can listen to here:
http://thespaceshow.com/detail.asp?q=680

I am still doubting if the energy balance really allows for economical vehicles powered this way.

It has been said that the huge energies required to ignite a fusion power plant are need only once. While this may be correct regarding a power plant to provide electricity only this is NOT valid regarding space vehicles.

Space vehicles start their engines and shut down them later when they have reached their destination. Then they have to fire their engines oince more and so on. This also holds for expendables.

This means that the huge amount of energy required to ignite the fusion(s) would be needed very often.

This means that the huge amount of energy required to ignite the fusion(s) would be needed very often.

Not sure it follows that just because the engines are switched off it is necessary to power the fusion power plant down. It might be OK to keep it running but with its output disconnected or powering something else.

This would only work for a reactor producing electricity rather than superheated gases expelled as thrust. I have seen designs where a gas is used to cool a nuclear core and then expelled to give thrust, obviously in such engines turning the gas supply off would cause the engine to overheat.

_________________A journey of a thousand miles begins with a single step.

All electrostatic confinement methods are non thermal equilibrium plasmas. Without Addressing these issues then its hard to take seriously. Note that I have run though the calculations, its very hard to discount out of hand. At the very least you would expect some supporting calculations or why his method will work when others have shown it won't.

To sum up, the fusion cross sections are just too low. To keep the plasma out of thermal equilibrium means you need to pump in large amounts of energy. And thats more than you get out. Unless you can convince me that scattering won't push the energy distribution of the ions closer to equilibrium I just won't buy it.

There are other problems too. If it will scale so well then the Russians should have seen better yields in there large systems. Hes no crack pot, but hes just been out of the loop for too long. But i do agree with his views on ITER however.

ITER scales so badly that the smallest size is likely to be rather uneconomic. So that approach does not impress me that much either. Not to mention the massive high energy neutron flux that is produced.

At any rate, its easy to produce fusion. Its hard to get useful fusion.

There is one interesting thing about the above papers etc. It considers steady state. Inertial confinement or non steady may be away around the problem. And we have a working example: Fusion weapons.

Unfortunately I think that beamed energy may be a better way to go. Or fission.

Unless you can convince me that scattering won't push the energy distribution of the ions closer to equilibrium I just won't buy it.

The fact that the development of the magnet insulation was in my view inexplicably and agonizingly slow, statements to the effect that it can't be simulated (directly or indirectly?) and that there are (yet to be explained) reasons why it won't thermalize etc. also leave me thinking it's actually a rather unlikely prospect.

According to the article "Friendly 'Death Star' Laser to Recreate Sun's Power" an experiment wil start in the nearby future at Lawrence Livermore National Laboratory in California in the National Ignition Facility.

Oops! Should have read this before posting. I intend to build one and test this out in the future. I belive this will work in the short term believe it or not. I think this is the right path for now. Hopefully we will find out!

the large chamber will be of large mass - compared to a smaler chamber.

The chamber to be seen in the image is significantly larger than the F-1 and the walls ae much more massive than those of the F-1.

This will be a problem.

Next there might be another problem too - to propell a vehicle the products of the fusion must leave the chamber as a jet of exhaust. How to that without contact between the exhaust and the walls? Because the event of fusion takes place only seconds before leaving any contact to the walls wil be destructive because of the extreme temperatures.

I have seen jets of particules fly out of a fusor in star mode. There for there must be a way to induce the jet where you want it. I dont really know yet but I think there may be a way to get lower power fusor to work for low impulse long duration.